At present, radio communication systems such as cell-phone systems are widely used. For attaining a further speeding up and wider bandwidth of radio communication, lively discussion is continuously performed about a next generation radio communication technology. For example, in a 3GPP (3rd Generation Partnership Project) being one of standard-setting organizations, there are proposed a radio communication system referred to as an LTE (Long Term Evolution) and a radio communication system referred to as an LTE-A (Long Term Evolution-Advanced) obtained by developing the LTE (see, for example, 3rd Generation Partnership Project, “Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E-UTRAN)”, 3GGP TR 25.913 V7.3.0, 2006-03 and 3rd Generation Partnership Project, “Requirements for further advancements for Evolved Universal Terrestrial Radio Access (E-UTRA)”, 3GPP TR 36.913 V8.0.1, 2009-03).
The above-described radio communication technology is used not only in radio communication through a terminal device operated by a user such as a cell-phone but also in radio communication through other various devices such as measurement devices. For example, a measurement device such as a gas meter or electric meter is considered to implement a system which reports measurement data to a server via a radio communication network. In 3GPP, an MTC (Machine Type Communication) is proposed as a mode of radio communication without an interaction with users (see, for example, 3rd Generation Partnership Project, “Service requirements for machine-type communications”, 3GPP TS 22.368 V1.0.0, 2009-08).
Incidentally, when data is not transmitted and received, a radio communication apparatus moves to a state (an idle state) of releasing a connection with regard to radio communication. The radio communication apparatus in the idle state establishes the connection again when a predetermined procedure (transmission and reception of messages) is performed between its own apparatus and a radio communication apparatus of communication partner.
However, in the case where the radio communication apparatus intermittently transmits data, when the establishment and release for the connection are performed in every data transmission, overhead becomes large due to a procedure for establishing and releasing the connection, and efficiency of the data transmission is reduced. Particularly, as in an MTC system, in a radio communication system in which the amount of data to be transmitted once is supposed to be relatively small, the above-described overhead reflects a large influence on the data transmission efficiency